Comparisons among organic acids

Despite their various chemical structures, all organic acids inhibit microorganisms in a similar fashion. For example, all show increased inhibition at low pH, microbes are inhibited rather than killed, lag phases are prolonged, yields reduced, and active transport prevented (Stratford and 

In the case of the organism Y. enteric, at high pH (5.8) the order of inhibition was reported to be formic acetic propionic lactic, whereas at lower pH values it became formic lactic acetic propionic (El-Ziney, De Meyer, and Debevere, 1997). In another study sodium benzoate was found to be more effective at inactivating E. coli 0157 H7 than potassium 

The alkyl esters (methyl, ethyl, and propyl) of p-hydroxybenzoic acid (the parabens) are widely used for their antifungal properties. The preservative effect of parabens tends to increase with increasing molecular mass. The methyl ester appears to be more effective against molds, whereas the propyl ester is more effective against yeasts (favored for oils and fats, for solubility reasons) (Gonzalez, Gallego, and Valcarcel, 1998). 

Abbott, D. A. and Ingledew, W.M. 2004. Buffering capacity of whole corn mash alters concentrations of organic acids required to inhibit growth of Saccharomyces cerevisiae and ethanol production. Biotechnology Letters 26 1313-1316. 

and Nicolaides, L. 1997. Review of the sensitivity of different food borne pathogens to fermentation. Food Control 8 227-239. 

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Since PCBs are adsorbed on the particle surface, normally coated with a thin layer of organic matter such as humic acid, the concentration in sediment and soil samples is much more likely to be related to the particle surface area per volume unit than to the mass unit. ° For this reason, the concentration of each sample, expressed in pgg dry weight, is normalized by dividing it by the relevant calculated specific surface area, expressed in square meters of surface per cubic centimeter of dry sample (m cm ), as obtained by particle size analysis. Comparisons among concentration values of organic pollutants relevant to samples with different particle size distribution may lead to erroneous conclusions if these are expressed in a conventional way. °... 

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